For a better understanding of the characteristics of weather simulation data we have created a subsection which explains the difference between simulated and measured weather data.

Characteristics of weather simulation data

This page gives an overview of:

Weather simulation data - what's that?

Why meteoblue simulation data is comparable to measurement data

Quality comparison: simulation data vs. measurement data

Profiles of grid cells with simulation data and measurement data

Calculation of simulation data

Availability of meteoblue simulation data vs. measurement data

Applications for simulation vs. measurement data

Weather simulation data – what’s that?

grid cells and weather stations

Basically, meteoblue forecasts are calculated with own models, not from individual weather stations. These weather models are based on the NMM (Nonhydrostatic Meso-Scale Modelling) or NEMS (NOAA Environment Monitoring System) technology, which enables the inclusion of detailed topography, ground cover and surface cover. Each forecast is archived by meteoblue at least once a day. From this data, we create a complete hourly history of the weather situation, which we can deliver for every place in the world from 1984 until today.

Official and reliable weather stations are scarce, and most of the weather station measurement data is useful only for a radius of 3 to 12 km surrounding the station. This means that less than 1% of the worlds surface is covered by measured data. For the atmosphere, much less measurement data exists. Since weather stations are located unevenly on land surfaces, you will find just a few places with weather stations in the vicinity. In most areas, stations are widely spaced and there are many places (especially in South America / Africa / Asia / unpopulated areas) where you will not find any weather station in the vicinity.

meteoblue weather simulations, however, cover the whole Earth surface, including the sea and mountainous areas. Therefore, meteoblue can offer forecast and historical data for any place in the world, including the atmosphere above us.

Why meteoblue simulation data is comparable to measurement data

There are a lot of reasons why the meteoblue simulation data is comparable to measurement data. The most important criteria are shown in the table below:

meteoblue simulation data

weather station measurement data

Spatial resolution

3 - 30 km

< 1 km

Worldwide coverage

100%

< 1%

Number of weather variables

45+

< 10

Number of years

> 30

2 - 30 (with gaps)

Time intervals

hourly, 3 hourly, daily

(hourly), 3 hourly, daily

Completeness

100%

10 - 99%

Consistency

100%

variable

Quality comparison: simulation data vs. measurement data

The first picture shows where weather station measurements and meteoblue simulation data is available. meteoblue simulation data is available worldwide (resolution), whereas rmeasurement data is only valid for an area of 1 to 3 km around a weather station. The colour shows the temperature deviation from measurements and simulation data to real temperature.

The second picture shows the quality of simulation data with MOS postprocessing. The temperature deviation can be reduced by weather measurement data (data must be available at least for one complete year). meteoblue uses gridded MOS for most of the Earth's surface, so you can expect the same precision in most areas, based on our very thorough evaluation of the precision of temperature simulations. The results are validated daily at all locations where measurements exist (which varies largely). However, the verification does not have any influence on the simulation model data itself as the meteoblue-models are no reanalysis datasets (where the forecast is merged with observations). We currently keep all models untouched as many of our customers want the raw historical data to train simulation models. If reanalysis data is desired, we can offer the ERA5 dataset which is produced by the ECMWF.

Profiles of grid cells with simulation data and measurement data

Calculation of grid cell data in flat terrain

Forecast data: meteoblue can calculate weather data for every point with a specific altitude in the grid cell.

Archive data: meteoblue archives each forecast data set at least once a day. The archive data is calculated for the average altitude of the grid cell (see “average temperature of the grid cell" in the charts below). The temperature deviance for flat terrain is between 0 and 2 K.

Calculation of grid cell data in mountainous terrain

Forecast data: meteoblue can calculate weather data for every point with a specific altitude in the grid cell (see “point temperature at specific location” in the charts below).

Archive data: meteoblue archives each forecast data set at least once daily. The archive data is calculated for the average altitude of the grid cell (see “average temperature of the grid cell" in the charts below). The temperature deviance for mountainous terrain is between 0 and 5 K.

Flat terrain

Mountainous terrain

Forecast data

Forecast data calculated for every point in a grid cell

Archive data

Forecast data calculated for the average of a grid cell

Temperature deviance

0 - 2 K

0 - 5 K

Calculation of simulation data

Forecasts can be highly inaccurate for a forecast horizon of just 10 days, so how could meteoblue compute 30 years of historical data? In fact we only compute a 1 day forecast, starting from real weather observations. This short term forecast has been validated against 10’000s of weather stations over many years, and is very close to reality (it corresponds to a reanalysis dataset, which is equivalent to the best possible forecast available for the day-ahead). We repeated this procedure for every day of the year for 30 years. That makes 8'760 one-day forecasts per year, which are then joined together into a continuous >30-year time series since - the meteoblue weather history.

Calculation of weather simulation data

Availability of meteoblue simulation data vs. measurement data

meteoblue simulation data is available without any gaps since 1984 from our global model (NEMSGLOBAL). This global model has a resolution of 30 km and we offer more than 30 years of hourly data.

Availability of meteoblue simulation data vs. measurement data

Applications for simulation vs. measurement data

meteoblue simulations can replace measurements in most areas. A simulation will be more precise for a given place than measurements taken 20 or more km away (in mountain areas, the simulation is already more accurate than a measurement at a distance of 3 - 10 km away). In places with very high need for reliability, such as airports, city centres, building management, irrigation systems, renewable energy production sites, high traffic roads and some others, the additional precision offered by measurements justify the (substantially) higher cost.